"It's weird. It's not so much about excitement, although I'm excited for every week and milestone. It's bittersweet and you don't really understand it until you're in it,” the "Dads" star explained while out at the Fox Fall Eco Casino party on Sept. 9. "Now I get what people are saying -- time flies by. Enjoy it while you can! I'm like, 'Oh hodge podge' and now I'm like 'What? He's going to be 1!'"

The doting mom, married to 98 Degrees band member Nick Lachey, may be in shock that her tot's already a year old, but that doesn't mean she hasn't had time to plan a celebration.

"We're going to do his party in Cincinnati and a lot of the family hasn't seen him yet because we've been working or on tour. So, it's going to be a big birthday party, probably bigger than I would like," Vanessa said in Los Angeles at Bungalow.

The former "Total Request Live" host described her son's birthday bash, "almost like a sit and see where people come because they haven't met him yet.” She added, "Some of Nick's extended family hasn't met him and our friends. So it's going to be fun. It's going to be a big Cinci birthday."

The 32-year-old is even thinking ahead to next year. "I can't wait for party number two where I just throw a whole bunch of kids in the pool and we have a good time, and a cake," she joked.

Birthdays aside, Vanessa is just happy being a mom these days, gushing that her favorite part of motherhood is, "just in the mornings when he's got that facial recognition and he melts my absolute heart with his excitement to see me. I'm like, 'Yes! Mama's still got it.'"